Apparatus for subjective examination of blood



July 30, 1940. L. sc A ET V 2,209,543

APPARATUS FOR SUBJECTIVE EXAMINATION OF BLOOD Filed Feb. 23, ess

( fnvemons: 2%-

Patented July 3Q14 azoaete ArrAnA'rUs Foa, SUBJECTIVE Exams.-

lfION OF BLOOD Leendert Schalm and Jan Frederik Schouten, Utrecht,Netherlands, assignors to the firm Carl Zeiss, Jena, Germany ApplicationFebruary 23.19%, Serial No. 192,112

In Germany March 2, 193? 3 Claims. (Ci. 88-14) Application has beenfiled in Germany March.

2, 1937. r The objective diagnosis of bloodis effected in hospitals bymeans of an apparatus according to Dr. Pijper, in which the diffractionrings of two blood smears are projected on a ground glass plate in suchreciprocal positions that isochromatic difiraction rings can be comparedas to their sizes. This testing apparatus provides very good results,but its dimensions prohibit physicians to -carry it along withthemselves when visiting patients in their homes.

The invention aims at providing a handy blood-cell testing apparatuswhich is especially simple in construction and permitssubjectiveexamination of blood and which physicians can carry in theirpocket.

The apparatus has to this effect a half-lens 29 corresponds to thecentre of the diffraction rings due to illumination of a comparisonblood smear in transmitted: light, and whose other division pointscorrespond to the points of intersection of the medial circles of thesediffraction rings the said image having the size in which the said scalewould be seen by the naked eye viewing the comparisionblood smearitself. Moreover, the apparatus has a construction permitting the imageof the scale and parts of the diffraction rings of the blood smear underexamination to be seen simultaneously in positions in which the centreof said rings coincides with the zero point of the scale, the magnitudeof the erythrocytes of theblood smear being found by comparison of theimage of the. scale and the magnitudes of the radii of the diffractionrings of the blood smear.

To measure the difierence in length between the radius of a definite,for instance the yellow, diffraction ring of the blood smear to beexamined and the distance apart of the image of the zero point of. thescale and the image of the 45 division point corresponding to the medialcircle of the diffraction ring of like colour-o1 the comparison bloodsmear, it is advisable to use another scale, which is linear andsuitably postioned with respect to the first said scale.

by holding this smear near the eye against a distant source of light (anordinary reading lamp).

forming an image of a scale whose zero point.

and a diameter of these rings which is parallel to the plane boundingsurface of the half-lens,

In the simplest case, the diffraction rings of the blood smear to beexamined can be produced The accompanying drawing illustratestwoconstructional examples of an apparatus according to the invention,the first example being represented by Figures '1 and 2 and the secondby Figures 4. and 5. Figure 1 is an elevational view, Figure 4 is alongitudinal section, and Figures 2 5 and 5 are side views 0f 'the markplate of the apparatus. Figures 3 and 6 illustrate the image whichthescale of the apparatus and the diffraction rings peculiar to the bloodsmear to be examined oifer the examiners 'eye in the first and thesecond example, respectively. y In Figures 1 and-2, l isa glass stafi ofrectangular cross-section. The face 2 of the stafi I is at right anglesto the longitudinal axisof same, and the face 3 is a part of the surfaceof a lens whose optical axis X X lies in the lateral surface 4 of thestall" I. 5 is asupport for a glass plateft. The face 2 bears threecircular lines R, B and 'G concentric to a pointM in the optical axisXA-X. R and B are quadrants, and G isa semi-circle. The face 2 isprovided alsowith .a linear scale I, a portion of this scale beingdisposed on the diameter of the semi-circle G. Thelens surface 3 hassuch a radius'of curvature and the circular lines R, G and B have suchradii that'an observer's eye A is offered the view of a sharp image ofcircular lines which meet the magnitudes in which the medial circles ofsimui-- taneo'usly visible red, yellow and blue diffraction rings wouldappear to the eye A looking at the glass plate 6 illuminated by adistant light-source if this plate were provided with a smear of bloodhaving normal-sized erythrocytes.

The apparatus is used as follows. The glass plate 6 is provided with asmear of the blood to be examiner, and the glass stafl I is so heldagainst adistantlight source that the observer's eye A (cf. Figure 3) isoffered the view of the diffraction rings which are peculiar to theblood under examination (and the medial circlesR", 0

IG" and B" of whose red, yellow and blue rings,

respectively, are shown in Figure 3 of the drawing) and that the eye Asees simultaneously therewith images R, G and B of the circular g linesR, G and-B, respectively, and an image 'I' of the ,scale I. In Figure 3,it is assumed that the erythrocytes of the blood to be examined are toogreat, which follows from the, diameters of R", G" and B" being smallerthan-the diameters or R, G and B. The difference of the radii 9;

of G" and G: can be read on the image I of the scale I.

In the blood-cell tester according to Figures!" f and s, acylindricaltube 8 contains in its two ends a mark plate 9 and a. half-lens Ill,respectively. mule tube a is a slit-tor the insertion of the field viewwhich is not occupied by the halt-lens II.

Themark plate I has on a straight line lying in the plane containing theoptical axis x-:: and the plane surface I! oi the hall-lens ll threedivision linear, a and b which. when the glass plate I I is providedwith a smear oi blood having normal-sized erythrocytes and the observerholds the tube 1 against a distant light source; are imaged in the eyeAct the observer by the halflens I. sharply, so as to appear to theobserver as tangents r, a and b to the medial circles r", a" and b",respectively, of the red, Yellow and blue diffraction rings,respectively. which are presented to the observer's view at the sametime. This case is shown in Figure 6. When, in the test of the smear ofthe blood under examination.

the images 1'', a and b of the division lines 1', 0 and b, respectively,diiier from the'tangents to the said medial circles, this diiierence isindica.-.

tive oi the said blood not being in order.

We claim: 1. A pocket apparatus for subjective determination of thesize-oi blood corpuscles, comprising a half-lens. a transparent markplate; one surface of said plate lying in the focal plane of saidhalt-lens and being provided with a non-linear scale, said half-lens andsaid scale lying on one i no side of an axial plane containing theoptical axis and the plane bounding surface 01 said half lens, means forrigidly connecting said plate to said halt-lens and having means forholding a transparent blood-smear carrier near said halfill a,aoa, c4a

prising a hall-lens. a transparent mark plate,

one surface 0! said plate lying in the focal plane of said halt-lens andbeing provided with a nonlinear scale, said hali lens and said scalelying on one side of an axial plane containing the optical axis and theplane bounding surface of said halt-lens, means for rigidly connectingsaid plate to said half-lens and having means for holding a transparentblood-smear carriernear said halt-lens, said carrier and said half-lenslying on opposite sides of said axial plane and permitting asimultaneous view of an image of said scale and the diil'raotion ringsdue to an illumination in transmittedlight of blood smeared on' saidcarrier, the division lines of saidscale constituting concentriccircular curves originating in. said'plane, and the images of saiddivision lines coinciding with-the diffraction rings formed by a smearoi blood having erythrocytes of normal size.

3. A pocket apparatus for subjective determi- 1 nation of the size ofblood corpuscles, comprising a half-lens, a transparent mark plate, onesur-- face of said plate lying in the focal plane of said halt-lens andbeing provided with alinear scale and a non-linear scale. said half-lensand said two scales lying on one side of an axial plane containing theoptical axis and the plane bounding surface of said half-lens, meansfor' rigidly connecting said plate to said half-lens and having meansfor holding a transparent blood-smear carrier near said hall-lens, saidcarrier and said half-lens lying on opposite sides of said axial planeand permitting a simultaneous view of an image of said scales and thediifraction rings due to an illumination in transmitted light of bloodsmeared on said carrier, the division lines of said scales originatingin said plane, the point of origin of a division line of one of saidscales coinciding with the point of origin of a division line of theother scale. and the images 01' the division lines of said non-linearscale coinciding with the diffraction rings formed by a smear of bloodhaving erythrocytes of normal size.

L. SCHALM.

J. F. SCHOUTEN.

